The 28-year-old from Boulder, Colo., who set his marathon best of 2:12:03 at last fall’s Chicago Marathon, ran away with this morning’s XSport Fitness Rock ‘n’ Roll Chicago Half Marathon presented by HumanaVitality in 1 hour, 5 minutes and 41 seconds. Eggleston, who will represent the United States in the marathon at next month’s IAAF World Championships in Moscow, Russia, surged just after the 10K mark to pull away from eventual second-place finisher Robert Wambua of Kenya (1:07:51).

“I was at my limit running 4:55-5:00 pace,” admitted Eggleston, who dumped water on his head frequently throughout the race in an effort to stay cool in the warm, sometimes windy conditions. “But when I’m marathon training it takes me a while to get going, but once I get into it I feel pretty good. The first third of the race was really tough, but around 10K I started to feel a little bit more like myself. Once we got through the city and hit 7 miles I felt great.”

A six-man pack, which included Eggleston, Wambua, American Fernando Cabada (3rd, 1:08:22), and Kenyans Elly Sang, Abraham Kiprop Rutto and Edwin Some, ran together through 5K in 15:44. By four-and-a-half miles Wambua and Eggleston had separated themselves from the field and began exchanging a series of innocent surges. Turning onto Michigan Avenue just past the 10K mark, Eggleston fed off the energy of the crowd and threw his knockout punch, quickly opening up a sizable gap on Wambua, an advantage he would extend all the way to the finish line.

“I wanted to give the fans a chance to see USA pull away from Kenya,” Eggleston said of his decisive move. “And I hit him hard. That’s what I hope to do four weeks from now.”

In the women’s race, the second time was the charm for Dani Fischer of Eau Clair, Wisc., as the 24-year-old former steeplechaser from the University of Wisconsin-Madison led from start to finish to win convincingly in 1:18:33. It was over a one-minute improvement for Fischer, who finished third here last year in 1:19:35. Erin Heenan of Ann Arbor, Michigan finished second in 1:19:54, just two seconds ahead of third-place finisher Lauren Versweyveld.

“Running through the city is just great,” said Fischer, who will shift her focus toward sprint and Olympic-distance triathlons for the remainder of the summer. “Those buildings just block the wind for you and the course support is amazing. To come down here and race is just fabulous.”

Fischer blazed through the first 5K in 18:10, with Heenan 15 seconds back and Versweyveld another 4 seconds behind her. Fischer extended her lead by another 25 seconds over the next 3.1 miles, passing the 10K mark in 36:37, 40 seconds up on Heenan, who continued to hold a slight advantage over Versweyveld. Fischer passed 10 miles in 59:36 and then closed her final 5K in 18:57 to claim victory.

“I was shooting to improve and I knew I’d be right up there,” said Fischer, who set her half-marathon PR of 1:17:52 earlier this year at the Hoosier Half Marathon. “I always shoot to win. I started feeling crappy around 9 to 10 miles but you’ve just gotta gut it out at the end.”

Twenty-thousand entrants took part in the fifth annual event that was run exclusively on the streets of downtown Chicago, including a handful of celebrities. Three-time Superbowl champion Roger Craig (wearing bib #33) finished in 1:51:22, Danni Allen, winner of season 14 of The Biggest Loser, crossed in 1:53:32, while NBC sports reporter and Access Hollywood correspondent Michelle Beadle, who was running for ASPCA, clocked 2:28:02.